package com.lmsservice.controller;

import com.lmsservice.common.R;
import jakarta.servlet.ServletOutputStream;
import jakarta.servlet.http.HttpServletResponse;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

@RestController
@RequestMapping( value = {"/common","/backend/common","/front/common"})
public class CommonController {

    @Value("${cookieshop.path}")
    private String basepath;

    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){
        //原始文件名
        String originalName =  file.getOriginalFilename();
        String suffix =  originalName.substring(originalName.lastIndexOf("."));

        //使用uuid重新生成文件名，防止文件覆盖
        String filename =  UUID.randomUUID().toString() + suffix;
        //创建一个目录对象
        File dir = new File(basepath);
        if (!dir.exists()){
            //目录不存在需要创建
            dir.mkdirs();
        }
        try {
            //将临时文件转存到指定位置
            file.transferTo(new File(basepath+ filename));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        return R.success(filename);
    }

    //文件下载
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response)  {

        try {
            //输入流，通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basepath+name));

            //输出流，通过输出流将文件写回浏览器，在浏览器展示图片
            ServletOutputStream outputStream = response.getOutputStream();

            response.setContentType("image/jpeg");

            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            //关闭资源
            outputStream.close();
            fileInputStream.close();
        } catch (FileNotFoundException e) {
            throw new RuntimeException(e);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

    }
}
